export default {
	//为当前模块开启命名空间
	namespaced: true,
	
	//模块的state 数据
	state: () => ({
		//购物车数组，用来存储购物车中的每个商品信息对象
		//每个对象都包含如下 6 哥属性：
		// { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state  }
		cart: JSON.parse(uni.getStorageSync('cart') || '[]'),
	}),
	
	//模块的 mutations 方法
	mutations: {
		saveToStorage(state) {
			uni.setStorageSync('cart',JSON.stringify(state.cart))
		},
		addToCart(state,goods) {
			//根据商品的Id，查询购物车中是否存在这件商品
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
			
			if ( !findResult ) {
				state.cart.push(goods)
			} else {
				findResult.goods_count++
			}
			// console.log(this)
			this.commit('m_cart/saveToStorage')
		},
		//更新购物车中商品的勾选状态
		updateGoodsState(state,goods) {
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
			
			if ( findResult ) {
				findResult.goods_state = goods.goods_state
				this.commit('m_cart/saveToStorage')
			} 
		},
		//更新购物车中商品的数量
		updateGoodsCount(state,goods) {
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
			
			if ( findResult ) {
				findResult.goods_count = goods.goods_count
				this.commit('m_cart/saveToStorage')
			} 
		},
		//根据商品Id从购物车中删除商品
		removeGoodsById(state,goods_id) {
			state.cart = state.cart.filter(x => x.goods_id != goods_id)
			this.commit('m_cart/saveToStorage')
		},
		//更新所以商品的勾选状态
		updateAllGoodsState(state,newState) {
			state.cart.forEach(item => item.goods_state = newState)
			this.commit('m_cart/saveToStorage')
		}
		
	},
	
	//模块的 getters 属性
	getters: {
		total(state) {
			// let c = 0;
			// state.cart.forEach(goods => c += goods.goods_count)
			// return c
			return state.cart.reduce((total,item) => total += item.goods_count, 0)
		},
		//勾选的商品数量
		checkedCount(state) {
			return state.cart.filter(x => x.goods_state).reduce((total,item) => total += item.goods_count,0)
		},
		//统计已勾选商品的总价
		checkedGoodsAmount(state) {
			return state.cart.filter( x => x.goods_state).reduce((totalprice,item) => totalprice += (item.goods_count * item.goods_price), 0).toFixed(2)
		}
	},
	
}